Cyclone Kyarr may keep Mumbai air cleanest in 5 years during Diwali

This Diwali, expect pollution levels to be the lowest that the city has known in five years, thanks to Cyclone Kyarr in the Arabian Sea.

This Diwali, expect pollution levels to be the lowest that the city has known in five years, thanks to Cyclone Kyarr in the Arabian Sea.

HT Image

In its forecast issued on Friday, the System of Air Quality Forecasting and Research (SAFAR) said, “The air quality during 2019 Diwali period is going to be one of the best in whole of western India, particularly in Pune and Mumbai as compared to past five years. This is mainly due to widespread rain, which is still continuing in Pune and Mumbai regions.”

The air quality index (AQI) for particulate matter (PM2.5 – fine particles that can enter the lungs and cause health ailments) on Saturday is expected to be 45; 75 on Sunday (Diwali); 104 on Monday; and 70 on Tuesday. The SAFAR categorises AQI levels from 0-50 as good, 51-100 satisfactory, 101-200 as moderate, 201-300 is poor, 301-400 is very poor, and above 401 is severe.

The most polluted areas in Mumbai will be Bandra Kurla Complex and Nerul, Navi Mumbai, and Shivajinagar and Lohegaon in Pune.

“External emissions in the form of firecrackers will deteriorate air quality to the moderate category a day after Diwali. However, under the influence of Cyclone Kyarr in the Arabian Sea, rain and moderate wind speed is likely to keep transportation of pollutants slow and subdued,” said Gufran Beig, project director, SAFAR. “For Mumbai and Pune, even as wind speed reduces and temperatures witness a gradual drop, the mixing layer of pollutants (pollution levels) closer to the surface will be kept in check due to high moisture and intermittent showers.”

SAFAR also predicted that the concentration of PM2.5 this Diwali is likely to surpass the safe limit of 60µg/m3 (microgrammes per cubic metre) only for a few hours (1am to 6am) on Monday (October 28). PM2.5 concentration on Saturday is expected to be 25µg/m3, 27µg/m3 on Sunday, and 63µg/m3 during the early hours of Monday. “Sudden change in monsoon dynamics will work positively to keep air quality in satisfactory range in spite of moderate fireworks,” said Beig.

SAFAR will be releasing another forecast on Saturday.

Last year, Mumbai recorded an AQI of 221 (poor) on Diwali (November 7, 2018), and 305 (very poor) AQI a day after Diwali. Mumbai recorded high pollution levels during Diwali 2017 when the AQI was 204 (poor) on Diwali (October 19, 2017) and 319 (very poor) a day after Diwali. In 2016, an AQI of 278 (poor) was recorded on Diwali day (October 30, 2016), and 315 (very poor) the day after. In 2015, the city recorded an AQI of 279 (poor) on Diwali day (November 11) and 313 (very poor) the day after.

WEATHER FORECAST

The India Meteorological Department (IMD) on Friday predicted the possibility of light to moderate rain for Saturday and light rain or thundershowers on Sunday, and intermitted showers likely to continue till Tuesday. “The deep weather depression (currently 300 km southwest of Mumbai) will convert into a cyclonic storm on late Friday night and re-curve towards the Oman coast leading to only light to moderate rain for the Konkan coast for coming days. This is the third cyclone in the Arabian Sea this year, which is a rare occurrence and is a clear indication of the impact of climate change,” said Anupam Kashyapi, head of weather, IMD Pune.

PREDICTED AQI FOR COMING DAYS

AQI on Friday – 47 (good)

Predicted AQI on Saturday – 45 (good)

Predicted AQI on Sunday (Diwali) – 75 (satisfactory)

Predicted AQI on Monday (a day after Diwali) – 104 (moderate)

Predicted AQI on Tuesday – 70 (satisfactory)

MOST POLLUTED AREAS IN MUMBAI DURING DIWALI: BKC and Nerul, Navi Mumbai

AREAS WITH CLEAN AIR IN MUMBAI DURING DIWALI: Worli and Colaba

(Source: SAFAR)